What Happens When A Mosquito Bites You

September 2, 1991|By LINELL SMITH, The Baltimore Evening Sun

While looking for blood under your skin, the mosquito constantly injects saliva to keep the blood from clotting as she feeds. This saliva contains proteins, which cause a reaction of itching and swelling. Scratching a bite makes it worse because it spreads the toxic material over a wider area.

According to reports in the Journal of Dermatology, there are immediate and delayed responses to mosquito bites. The immediate reaction resembles an acute allergic response, while the delayed reaction is more akin to poison ivy.

People who are bitten by enough mosquitoes slowly become immunized to their saliva. There are five common stages of reaction:

1. If you have never been exposed, you will get no reaction.

2. After limited exposure, you get a delayed reaction of intense itching and redness several hours after a bite.

3. Increased exposure to mosquito bites provides an immediate reaction in one or two minutes that only lasts an hour.

4. With more continual exposure, the delayed reaction vanishes.

5. After lots of exposure, some people get no reaction at all.

If you vacation away from home, you may find that the mosquitoes are more vicious than the ones you have become used to. According to Dr. Martin Valentine, clinical director of the Johns Hopkins Asthma and Allergy Center, mosquitoes in different locations carry slightly different proteins in their saliva.

REPEL BUGS:

Scientists suggest a few measures anyone can take to ward off mosquitoes:

Avoid nature walks at dawn and dusk. Some mosquitoes are crepuscular feeders, meaning they prefer dimly lighted times of day for stalking prey.

Keep an eye on potential mosquito breeding grounds. Stagnant water in plastic swimming pools and bird baths make splendid mosquito nurseries. The same goes for saucers under your flower pots. Be sure to keep the grass mowed.

Wear light-colored clothing. Some studies suggest that mosquitoes prefer large dark objects and may be sensitive to the color blue, as are some biting flies.

Take a shower. Entomologist Robin Todd has anecdotal evidence that mosquitoes will turn down newly washed skin in favor of flesh that offers a better bouquet of chemicals.